The Reactions of Methyl Radicals with the Hydrogen Isotopes

摘要

The photolysis of acetone has been studied in the temperature range 130–420°C. Measurements have been made of the rates of most of the possible reactions of CH3and CD3radicals with hydrogen, deuterium, and deuterium hydride. The following activation energies for the abstraction of a hydrogen or deuterium atom have been found: CH3+acetone, 9.7; CD3+dacetone, 11.6; CH3+D2, 11.8; CD3+H2, 11.1; CH3+HD→CH4, 10.0; CH3+HD→CH3D, 11.3; CD3+HD→CD3H, 10.7; CD3+HD→CD4, 10.7 kcal. The steric factors are all of the order of 10−3. The results are discussed in terms of isotope effects with particular reference to the deuterium hydride reactions.